CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Statement of Comprehensive Income [Abstract]
Net income	$ 56,453	$ 42,050	$ 60,490	$ 55,252
Other comprehensive income:
Amortization of defined benefit pension plans, net of tax of $148, $60, $298, and $120, respectively	385	154	770	308
Other comprehensive income, net of tax	385	154	770	308
Comprehensive income	56,838	42,204	61,260	55,560
Comprehensive loss attributable to noncontrolling interest	(12)	(118)	(12)	(247)
Comprehensive income attributable to California Water Service Group	$ 56,850	$ 42,322	$ 61,272	$ 55,807

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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